The present invention concerns a lockable elastic joint for anthropomorphous robot serving industrial machines, particularly for sheet metal machining machines and even more particularly for bending machines.
By the term xe2x80x9canthropomorphous robotxe2x80x9d a robot for industrial machines is meant that has the ability to execute all the movements of a human arm, and in particular those of the articulations of elbow and wrist.
Anthropomorphous robots are increasingly used in the industry in order to replace the human intervention on machines of various kind, in particular for the loading and the unloading of the pieces being machined.
An example of this use is given by the machines for the machining of sheet metal and in particular by bending presses, where it has the task of handing the sheet metal to be bent, to accompany it in its movements during the bending stage and finally to remove it from the machine once the bending has been made.
The problem with robots used in this way consists in the fact that a robot is provided by its own nature with precise movements that are pre-set during the programming stage, while the part of sheet metal submitted to bending has a movement that varies both with the type of bending as well as with the nature and the thickness of the sheet metal.
Therefore it has been demonstrated to be necessary to interpose an elastic joint that is lockable on command between the wrist and the handling organ or hand of the robot, that allows the robot to accompany gently and with flexibility the movement of the sheet metal during the bending stage, while at the same time maintaining the precision of movement during the stage of loading and unloading of the sheet metal.
In view of this state of the art object of the present invention has been to provide a lockable elastic joint that is particularly suitable for the aforementioned use.
According to the present invention such object has been reached by means of an elastic lockable joint for anthropomorphous robot provided with wrist and with handling organ, comprising a first part that is fastenable to the wrist of the robot and a second part that is fastenable to the handling organ of the robot, characterised in that it comprises first coupling means between said parts suitable to maintain the same parts at a pre-established distance and on planes parallel to each other and second coupling means between said parts suitable to allow in an elastic way or, as an alternative, to prevent mutual movements of said parts along two directions parallel to the planes of the two parts and perpendicular to each other and around an axis perpendicular to the aforesaid planes.
In this way the two parts are allowed to move elastically with respect to one another while maintaining the co-planarity and the mutual distance, as required in order to gently accompany the movements of the sheet metal during the bending stage. At the same time their mutual locking in a fixed position is possible, as required during the stages of loading and unloading of the sheet metal.
In addition there are preferably provided means suitable to lock the two parts in any position decentralised with respect to one another.